This invention relates to a floor system for a grain storage bin and more particularly to a floor system utilizing interconnected floor channels and free-standing floor supports.
Grain storage bins are typically made of corrugated sheet-metal panels bolted together to form a right cylindrical bin and have a conical roof, and are supported on a concrete pad or foundation. As is conventional, an air-permeable grain-supporting floor is provided in the bin above the concrete pad so as to form a plenum chamber between the concrete pad and the grain floor. A fan and air heater assembly located outside the grain bin blows heated air into the plenum so that the heated air flows up through the floor and into the grain for drying or otherwise conditioning the grain. Typically, the grain floor is located about 12 to 18 inches (30 to 45 cm.) above the concrete pad so as to provide a plenum of sufficient height and volume that the static pressure therewithin is substantially uniform under the entire area of the grain floor.
While grain floors have been of various configurations, this invention is particularly concerned with grain bin floors made of elongate, prefabricated metal channels which interlock in side-by-side relation to form a continuous grain floor. Heretofore, these interlocking grain floor channels have been supported above the concrete pad in a variety of ways including stacking concrete blocks on the concrete pad at specified locations to support the floor. More recently, metal supports legs have been used which are free standing on the concrete pad and which engage the bottom of the grain floor channels thus eliminating the use of concrete blocks and permitting air to circulate freely in the plenum. Further these prior free-standing support legs are fast to install because they do not need to be bolted or otherwise fastened to the concrete pad or to the floor members, and no lateral braces between the supports are required.
However, in actual use a serious problem with these prior free-standing support legs has, on occasion, been encountered which has resulted in the catastrophic failure of the grain bin floor upon filling of the bin with grain. More particularly, it is a common practice for the user of a grain bin to test the fan and heater system prior to filling the bin. Upon start-up of the fan, the static pressure in the plenum chamber beneath the grain bin floor is, in many instances, sufficient to lift some or all of the floor in an empty bin up from the free-standing support legs. Since the support legs are free standing (i.e., they are not secured to the concrete pad or to the grain floor), air circulating in the plenum chamber could blow over some of the support legs. Upon turning off the fan, the floor would settle and would be supported in its proper position by the remaining support legs. Since the legs are hidden from view, there is no visual way to check the grain bin to ascertain if the support legs are properly positioned. Upon filling the bin with grain, the weight of the grain would cause a portion of the grain bin floor not properly supported by the support legs to fail, thus spilling the grain into and partially filling the plenum chamber. If the failure is not detected, a large portion of the grain may not be properly dried. Of course, if the failure is detected, the bin must be unloaded and the damaged floor replaced. The unloading of the filled bin with a collapsed floor is a time-consuming job and the repair parts for the grain bin floor may be expensive and require time to order. During the harvest season when the grain bin is primarily used for drying grain, time is of the essence and thus failure of the grain bin floor may not only result in damage to the grain bin, but spoilage of the grain to be dried therein.